SU1744123A1 - Method of deoxidizing molten metal mostly for round billets - Google Patents

Abstract

Usage: in the steel industry in the production of tubular blanks. SUMMARY OF THE INVENTION: A method for deoxidizing a liquid metal involves preliminary deoxidizing a metal in a furnace with silicon-manganese aluminum. the final deoxidation in the ladle with ferrosilicon and aluminum. Deoxidation begins with a mass fraction of manganese 0.06-0.20%, while the ratio of the mass fraction of manganese introduced by silicon-manganese aluminum to the mass fraction of manganese in the metal before deoxidation is 3-10, and the ratio of the amount of aluminum introduced into the furnace and ladle, equals 0.10-0.24. 1 tab. (Ls

Description

This invention relates to ferrous metallurgy, in particular, to the process of deoxidizing calm steel in an open-hearth furnace for the production of tubular billets.

The purpose of the invention is to improve the quality of the metal.

When smelting pipe steels, and they belong to low and medium carbon brands, there is a significant reduction in manganese due to a hotter smelting process, especially under conditions of bath purging with oxygen.

Due to the fact that all the manganese required to produce tubular steel is introduced during the preliminary deoxidation of the metal with silicomanganese aluminium, there is a relationship between the mass of the injected ferroalloy and the mass of manganese in the liquid metal. In turn, it depends on the mass of the injected ferroalloy how much will be introduced into the liquid

Si and AI bath. With a high mass fraction of manganese before silicon and aluminum are deoxidized, it is not enough to remove excess oxygen and the bath boils, which makes it difficult to get into the smelting analysis on carbon. In addition, metal deficiency leads to a deterioration in the quality of the metal and an increase in the loss of scavengers.

With a low mass fraction of manganese in the metal, before the deoxidation, the consumption of silicomargain-aluminum increases significantly, which leads to an increase in the duration of preliminary deoxidation due to poor dissolution of the ferroalloy. An increase in deacidification time affects the quality of the metal.

However, only the performance of the optimal ratio between manganese introduced by manganese silicon aluminum,

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manganese in the liquid metal before deoxidation is not enough to obtain high quality pipe billets. It is necessary to withstand certain ratios of the mass of aluminum introduced into the furnace 5 and the ladle. This is due to fluctuations in the mass of the ferroalloy and the mass fraction of aluminum in the ferroalloy (from 1.5 to 3-2%).

Studies show that to improve the quality of the metal due to the achievement of the optimum preliminary deoxidation time and the production of steel with a minimum degree of oxidation, it is necessary to begin the preliminary deoxidation of the metal with a mass fraction of manganese — 15.06-0.2% the proportion of manganese introduced by silicon manganese aluminum to the mass fraction of manganese in the metal before deoxidation should be 3-10, and the ratio of the mass of aluminum to 20 min injected into the furnace and ladle, -0.10-0.24.

To determine the effectiveness of the proposed method for the deoxidation of liquid metal, industrial experiments were carried out at the Kommunarsk Metallurgical Combine in the smelting of pipe steel 20 tr in 600-ton open-hearth furnaces with oxygen bath purging.

The results of the experiments. According to the determination of the efficiency of the proposed method for the deacidification of a liquid metal, see the table.

From the data in the table it follows that when the mass fraction of manganese in the metal before deoxidation is 0.06-0.20%, the ratio of the mass fraction of manganese introduced by silicomanganese aluminum to the mass fraction of manganese before deoxidation 3-10 and the ratio of the mass of aluminum introduced into the furnace and a ladle, 0.10-0.24, the proposed method of deacidification of a liquid metal provides an output of defect-free tubular billets by 5.2-10% higher than when using the known method of deacidification. At the same time, the duration of preliminary deoxidation is reduced by 7-13 minutes, and the consumption of silico-manganese-mini is reduced by 0.5-0.7 kg / t of steel.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION A method for deoxidizing a liquid metal mainly for billets, including preliminary deoxidation of the metal in the furnace with silicon-manganese aluminum, the final deoxidation in the ladle by ferrosilicon and aluminum, characterized in that, in order to improve the quality of the metal, the preliminary deoxidation of the metal begins at a mass fraction of manganese in the melt 0, 06-0.20%, while the ratio of the mass fraction of manganese introduced by silicon-manganese-aluminum to the mass fraction of manganese in the metal before deoxidation is 3-10, and the ratio The amount of aluminum introduced into the furnace and ladle is 0.10-0.24. one 2 3 $ 6 8 9 0 one rotop 2.9 3.0  ° M 6.0 9.0 10.0 10.0 10.1 8.0 ,about 0.21 oh go 0.20 0.16 0.11 0.07 0.06 0.06 0.05 0.10 0.20 15.0 0.04 0.0 $ 0.10 0.1 $ 0.12 0.18 0.20 0.2 0.18 0.25 0.25 0.09 0.30 10 12 10 It 15 18 20 IS 23 25 10 25 1630 1620 1620 1615 1615 1610 1600 1600 1590 1610 1615 1600 7 .. 7 7, in 6.8 6.0 5.7 6.5 6.8 7.0 7.0. 7.2 7.S 0.0015 0.0020 0.0010 0.0021 0.0024 0.0026 0.0025 0.0022 0.0016 0.0019 0.0016 0,001 $ SS.6 60.2. 60.0 silt 65,8 4 $. About ". About 65.0 58.1 55.5 46.1 55.0